Pathophys of ataxia and gait disorders

Question 1

CAUSES OF UNSTEADINESS

i) what are the three types of ataxia?
ii) name three orthopaedic problems (MSK) that can cause it?
iii) name three things that can cause cerebellar ataxia?
iv) name two peripheral and two central things that cause vestibular ataxia?
v) what is sensory ataxia? when may it be seen (2)
vi) name two extra pyramidal gait disturbances?
vii) name three things that can cause pyramidal gait disturbance
viii) three things that can cause LMN gait disturbance

Answer 1

i) cerebellar, vestibular and sensory
ii) antalgic gait eg hip arthritis, collapsing gait eg knee arthritis (giving way), spinal or leg deformity
iii) alcohol and drugs (anti convulsants eg long term phenytoin), stroke, paraneoplastic syndromes

iv) peripheral > vertigo eg labrinthitis and menieres disease
central > stroke, MS

v) decreased info into cerebellum due to damage to posterior columns or large fibres in peripheral nerves that bring proprioceptive info into the brain

vi) PD and things affecting SN and basal ganglia connections
- chorea (also cerebellar ataxia)

vii) cerebral palsy, stroke, MS, head injury, spinal cord injury

viii) nerve damage supplying muscles in lower lumbs eg motor neuropathy, lumbar radiculopathy, femoral/peroneal nerve > foot drop
- seen in B12 deficiency, cervical myelopathy

Question 2

ORTHOPAEDIC GAIT DISORDER

i) what type of gait is it?
ii) name two things that can cause it
iii) which phase of gait cycle is shortened?
iv) how may it appear

Answer 2

i) antalgic (avoiding pain)
ii) kyphoscoliosis and leg deformity/hypermobility
iii) stance and swing phase
iv) hobbling/waddling

Question 3

CEREBELLAR DISORDERS

i) what type of gait is seen?
ii) what four components are there of gait?
iii) what is rombergs sign?
iv) what may be seen on imaging?

Answer 3

i) ataxic gait
ii) very unsteady, broad based (hesitant, jerky), veering and truncal tremor when trying to maintain a posture

iii) increased problem with balance when eyes are shut as cut off one input to cerebellum
- ask patient to stand with heels together with eyes open and closed > see excessive postural swaying when eyes closed in proprioceptive deficit
(if it is there when eyes are open or closed then its cerebellar ataxia)

iv) cerebellar atrophy (can be due to alcohol)

Question 4

HEMIPLEGIC GAIT

i) which MNs are affected?
ii) how is the foot held? what happens at the knee?
iii) what compensatory mechanism occurs
iv) what is it often accompanied by

Answer 4

i) unilateral upper motor neurons
ii) plantar flexion of foot and stiffness of knee
iii) circumduction > leg swings out
iv) hemiplegic upper limb > flexion at elbow and wrist (extension in lower limb)

Question 5

DIPLEGIC GAIT

i) what is it?
ii) name two things that can cause it? which spinal pathway is implicated?
iii) what gait is seen? what happens to the legs

Answer 5

i) spasicity on both sides of the body
ii) cerebral palsy (hypoxic event) and spinal cord damage (disk protrusion) lateral corticospinal tract
iii) legs internally rotated and scissoring gait

Question 6

PARKINSONIAN GAIT

i) what type of gait is seen?
ii) what happens in the legs? (2)
iii) what happens as parkinsons progresses?
iv) which nucleus in the thalamus does the BG output to?

Answer 6

i) shuffling gait
ii) legs dont lift, smaller steps > trip over on uneven ground
iii) lose ability to make corrections and can dissapear all together in advanced parkinsons
iv) ventrolateral nucleus of the thalamus > loop back to supplementary motor cortex which sets up postures

Question 7

HIGH STEPPING GAIT

i) what is it also known as
ii) which nerve may be damaged?
iii) name four things that can cause it

Answer 7

i) foot drop
ii) tibial/peroneal
iii) ruptured disk, sciatic nerve tumour, total hip replacement (toe drop), traumatic knee injury

Question 8

WADDLING/TRENDELENBURG GAIT

i) what is it?
ii) what compensation causing waddling gait
iii) what is trendelenburg sign?
iv) which muscle is implicated in this gait
v) what type of gait disturbance is it?

Answer 8

i) usually a compensatory gait > if you dont compensate you get a wiggle bottom gait (drop of pelvis due to gluteus medius)
ii) pelvis tips to one side so thorax moves to other side to compensate
iii) stand on one leg > pelvis drops to the opposite side
iv) gluteus medius muscle weakness
v) myopathic